6. LOADING AND INSTALLATION
MELSEC-A
I
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6.
6.1
6.2
LOADING AND INSTALLATION
This section gives procedures
and
precautions to be taken for
loading
and
installation of system modules to improve reliability
and
make the most of
system function.
Fall-safe
Circuit
Conduct system designing considering the following points and prevent
mis-input from remote I/O modules and remote terminal modules.
(1) Measure against mis-input at power on and off
(2) Measure against mis-input due to momentary power failure of remote
I/O modules or remote terminal modules (See Section 2.2, (6)
for
details.)
The system may malfunction when external power supply or the PC module
causes a failure. To prevent a circuit failure from developing which could
damage the whole system and to achieve a fail-safe system, construct those
circuits where failure will lead to breakage or accidents of machine equip-
ment (e.g., emergency
stop
circuit, protection circuit, interlock circuit) out-
side the PC.
Installation
Environment
Never install the A2C system modules in
the
following environmental condi-
tions.
(1) Locations where ambient temperature is outside
the
range 0 to 55·C.
(2) Locations where ambient humidity is outside the range of 10 and 90
%
RH
.
(3)
Locations
where
dew
condensation
takes
place
due
to
sudden
temperature changes.
(4) Locations where there are corrosive gasses and combustible gasses.
(5) Locations where there is a high level of conductive powder such as dust
and iron filings, oil mist, salt, and organic solvent.
(6) Locations exposed to the direct rays of
the
sun.
(7) Locations where strong power and magnetic fields are generated.
(8) Locations where vibration and shock are directly transmitted to
the
main unit.
6-1